refreshless-8.x-1.x-dev/modules/refreshless_turbo/src/StackMiddleware/AdditiveLibraries.php

<?php

declare(strict_types=1);

namespace Drupal\refreshless_turbo\StackMiddleware;

use Drupal\refreshless\Service\PageStateFactoryInterface;
use Drupal\refreshless\Service\RequestWrapperFactoryInterface;
use function array_search;
use function array_splice;
use function implode;
use function is_int;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpKernel\HttpKernelInterface;

/**
 * Additive libraries middleware.
 *
 * This loads the RefreshLess page state if found in the request, removes the
 * 'refreshless_turbo/refreshless' library from the already loaded list, and
 * then converts it to 'ajax_page_state' value, which it sets back on the
 * request.
 *
 * @see \Drupal\Core\StackMiddleware\AjaxPageState
 *   Must run after core's Ajax page state middleware; if we were to run before
 *   it, we would have to re-compress the libraries only for core to decompress
 *   it again which is a bit inefficient and unnecessary.
 */
class AdditiveLibraries implements HttpKernelInterface {

  /**
   * Constructor; saves dependencies.
   *
   * @param \Symfony\Component\HttpKernel\HttpKernelInterface $httpKernel
   *   The wrapped HTTP kernel.
   *
   * @param \Drupal\refreshless\Service\PageStateFactoryInterface $pageStateFactory
   *   The RefreshLess page state factory service.
   *
   * @param \Drupal\refreshless\Service\RequestWrapperFactoryInterface $requestWrapperFactory
   *   The RefreshLess request wrapper factory.
   */
  public function __construct(
    protected readonly HttpKernelInterface $httpKernel,
    protected readonly PageStateFactoryInterface $pageStateFactory,
    protected readonly RequestWrapperFactoryInterface $requestWrapperFactory,
  ) {}

  /**
   * {@inheritdoc}
   */
  public function handle(
    Request $request, int $type = self::MAIN_REQUEST, bool $catch = true,
  ): Response {

    if ($type !== self::MAIN_REQUEST) {
      return $this->httpKernel->handle($request, $type, $catch);
    }

    $requestWrapper = $this->requestWrapperFactory->fromRequest($request);

    try {

      $pageState = $this->pageStateFactory->fromRequest($request);

    } catch (\ValueError $exception) {

      $pageState = false;

    }

    if (
      !$requestWrapper->isRefreshless() ||
      $pageState === false
    ) {
      return $this->httpKernel->handle($request, $type, $catch);
    }

    $libraries = $pageState->getLibraries();

    /** @var int|false */
    $index = array_search('refreshless_turbo/refreshless', $libraries);

    if (is_int($index)) {

      array_splice($libraries, $index, 1);

      $pageState->setLibraries($libraries);

    }

    $ajaxPageState = [
      'libraries'   => implode(',', $libraries),
      // Explicitly leave out 'theme' because that would cause Drupal to keep
      // the user on whatever theme they started on, meaning we would never
      // switch between the default and admin themes causing all sorts of weird
      // and fun problems.
      'theme_token' => $pageState->getThemeToken(),
    ];

    if ($request->getMethod() === 'GET') {

      $request->query->set(
        'ajax_page_state', $ajaxPageState,
      );

    } else {

      $request->request->set(
        'ajax_page_state', $ajaxPageState,
      );

    }

    return $this->httpKernel->handle($request, $type, $catch);

  }

}